local lsp         = require('lspconfig')
local lspstatus   = require('lsp-status')
local navic       = require('nvim-navic')

local my_attach = function(client, bufnr)
  if vim.opt.diff:get() then
    vim.notify('not running LSP client in diff mode', vim.log.levels.WARN)
    vim.lsp.stop_client()
    return
  end

  local group = vim.api.nvim_create_augroup('LspOnAttach', {})
  vim.api.nvim_create_autocmd('CursorHold', {
    buffer = bufnr,
    group = group,
    callback = function()
      if not _G.diagnostic_hidden then
        vim.diagnostic.open_float(nil, {
          focusable = false,
          close_events = {'BufLeave', 'CursorMoved', 'InsertEnter', 'FocusLost'},
          border = _G.floating_win_border,
          source = 'always',
          prefix = ' ',
          scope = 'cursor',
        })
      end
    end,
  })

  lspstatus.on_attach(client)
  if client.supports_method('textDocument/symbols') then
    navic.attach(client, bufnr)
  end

  if client.supports_method('textDocument/definition') then
    vim.keymap.set('n', '<C-]>'     , vim.lsp.buf.definition, {buffer = bufnr})
    vim.keymap.set('n', 'gd'        , vim.lsp.buf.definition, {buffer = bufnr})
    vim.keymap.set('n', 'gR'        , vim.lsp.buf.references, {buffer = bufnr})
    wk_register({
      ['gd'] = {'goto definition'},
      ['gR'] = {'goto references'},
    }, {buffer = bufnr})
  end
  if client.supports_method('textDocument/hover') then
    vim.keymap.set('n', 'K'         , vim.lsp.buf.hover, {buffer = bufnr})
  end
  if client.supports_method('textDocument/rename') then
    vim.keymap.set('n', 'grr'       , vim.lsp.buf.rename, {buffer = bufnr})
    wk_register({
      ['grr'] = {'rename'},
    }, {buffer = bufnr})
  end
  if client.supports_method('signatureHelp') then
    vim.keymap.set('n', '<c-h>'     , vim.lsp.buf.signature_help, {buffer = bufnr})
    -- vim.keymap.set('n', ';s '       , vim.lsp.buf.signature_help, {buffer = bufnr})
  end
  if client.supports_method('textDocument/formatting') then
    vim.api.nvim_buf_set_option(bufnr, 'formatexpr', 'v:lua.vim.lsp.formatexpr()')
    vim.keymap.set('n', '<leader>f' , vim.lsp.buf.format, {buffer = bufnr})
    wk_register({
      ['<leader>f'] = {'format'},
    }, {buffer = bufnr})
    vim.api.nvim_create_autocmd('BufWritePre', {
      buffer = bufnr,
      group = group,
      callback = function() require('lsp').format(vim.fn.expand('<afile>:p')) end,
    })
  end
  if client.supports_method('textDocument/typeDefinition') then
    vim.keymap.set('n', 'gT'        , vim.lsp.buf.type_definition, {buffer = bufnr})
    wk_register({
      ['gT'] = {'goto typedef'},
    }, {buffer = bufnr})
  end
  if client.supports_method('textDocument/declaration') then
    vim.keymap.set('n', 'gD'        , vim.lsp.buf.declaration, {buffer = bufnr})
    wk_register({
      ['gD'] = {'goto declaration'},
    }, {buffer = bufnr})
  end
  if client.supports_method('textDocument/implementation') then
    vim.keymap.set('n', 'gI'        , vim.lsp.buf.implementation, {buffer = bufnr})
    wk_register({
      ['gI'] = {'goto implementation'},
    }, {buffer = bufnr})
  end
  if client.supports_method('workspace/symbol') then
    vim.keymap.set('n', 'gW'        , vim.lsp.buf.workspace_symbol, {buffer = bufnr})
    wk_register({
      ['gW'] = {'goto symbol'},
    }, {buffer = bufnr})
  end
  -- if client.resolved_capabilities.document_symbol then
  --   vim.keymap.set('n', 'g0', vim.lsp.buf.document_symbol, {buffer = bufnr})
  -- end
  if client.supports_method('textDocument/codeAction') then
    vim.keymap.set('n', 'ga', vim.lsp.buf.code_action, {buffer = bufnr})
    wk_register({['ga'] = {'code action'}}, {buffer = bufnr})
  end
end

local my_exit = function(_, _, _)
end

local capabilities = function()
  local caps = vim.lsp.protocol.make_client_capabilities()
  -- enable lsp-based snippets
  caps.textDocument.completion.completionItem.snippetSupport = true
  caps.textDocument.completion.completionItem.resolveSupport = {
    properties = {
      'documentation',
      'detail',
      'additionalTextEdits',
    }
  }
  -- add window/workDoneProgress capability
  caps = vim.tbl_extend('keep', caps or {}, lspstatus.capabilities)
  return caps
end

local servers = {
  ccls = { disabled = true,
    root_dir = lsp.util.root_pattern('.ccls','meson.build','.git'),
    init_options = {
      compilationDatabaseDirectory = "build",
      index = { threads = 0 },
      completion = {
        filterAndSort = false,
      },
      clang = { excludeArgs = { '-frounding-math' } },
    },
  },
  clangd = {
    root_dir = lsp.util.root_pattern('.ccls','meson.build','.git'),
  },
  elixirls = {
    cmd = { 'elixir-ls' },
    settings = {
      elixirLS = {
        dialyzerEnabled = false,
      }
    }
  },
  gopls = {
    settings = {
      gopls = {
        analyses = {
          --  composites = false,
          fieldalignment = true,
          nilness = true,
          shadow = false,
          unusedparams = true,
          unusedwrite = true,
        },
        gofumpt = true,
        -- hoverKind = 'Structured',
      }
    }
  },
  sumneko_lua = {
    cmd = { 'lua-language-server' },
    settings = {
      Lua = {
        runtime = {
          version = 'LuaJIT',
          path = vim.split(package.path, ';'),
        },
        diagnostics = {
          globals = {
            '_G',
            'error',
            'os',
            'package',
            'pairs', 'ipairs',
            'pcall',
            'require',
            'string',
            'table',
            'type',
            'vim',
          },
          neededFileStatus = {
            ['code-style-check'] = 'Any',
          }
        },
        format = {
          enable =  true,
          defaultConfig = {
            indent_style = 'space',
            indent_size = '2',
          }
        },
        workspace = {
          -- library = vim.api.nvim_get_runtime_file("", true),
          library = {
            [vim.env.VIMRUNTIME .. '/lua'] = true,
            [vim.env.VIMRUNTIME .. '/lua/vim/lsp'] = true,
          }
        },
        telemetry = {
          enable = false,
        },
      },
    },
  },
  rust_analyzer = {
    cmd = { 'env', 'CARGO_TARGET_DIR=/tmp', 'RUST_SRC_PATH=/usr/src/rustlib/library', 'rust-analyzer' },
    settings = {
      ['rust-analyzer'] = {
        checkOnSave = {
          command = 'clippy'
        }
      }
    },
  },
  tsserver = { disabled = true,
    cmd = {
      'toolbox', 'run', '--',
      'sh', '-c',
      '. /etc/profile.d/nvm.sh && typescript-language-server --stdio'
    },
  },
  zls = { disabled = true,
  },
  zk = { disabled = true,
    root_dir = lsp.util.root_pattern('.zk'),
  },
}

local setup = function()
  local caps = capabilities()
  for server, opts in pairs(servers) do
    if not opts.disabled then
      opts = vim.tbl_extend('error', opts, {
        on_attach    = my_attach,
        on_exit      = my_exit,
        capabilities = caps,
      })
      -- lsp-status custom handlers
      local ok, lspstatus_ext = pcall(lspstatus.extensions[server])
      if ok then
        opts = vim.tbl_extend('error', opts, {
          handlers = lspstatus_ext.setup(),
        })
      end
      lsp[server].setup(opts)
    end
  end
end

local format = function(afile)
  if vim.g.nofmt then return end
  if not string.match(afile, '^/home/robert/devel/upstream') then
    vim.lsp.buf.format()
    if string.match(afile, '.go$') then
      vim.lsp.buf.code_action({ only = {'source.organizeImports'} })
    end
    -- vim.notify('%#MoreMsg#󰃢%#Italic# fmt')
    vim.notify('%#MoreMsg#󰃢%#Italic# fmt')
  end
end

local symbols = {
  -- 󰆼  󱆃
  Array = '󰨾 ',
  Boolean = '󰦍 ',
  Class = '󰙀 ',
  Color = '󰉦 ',
  Constant = ' ',
  Constructor = '󱇿 ',
  Enum = ' ',
  EnumMember = ' ',
  Event = '󱐋 ',
  -- Field = '󰽜 ',
  Field = '󰆈 ',
  File = '󰈔 ',
  Folder = '󰝰 ',
  Function = ' ',
  Interface = '󱦜 ',
  Key = '󰌋 ',
  Keyword = '󰓽 ',
  Method = '󰒓 ',
  Module = '󰏖 ',
  Namespace = '󰆧 ',
  Null = '󰎣 ',
  Object = '󰘦 ',
  Operator = '󱓉 ',
  Property = '󰐱 ',
  Package = '󰏗 ',
  Reference = '󰌹 ',
  Snippet = '󰯁 ',
  Struct = '󰙅 ',
  Text = '󰉿 ',
  TypeParameter = '󰌨 ',
  Unit = '󰠱 ',
  Value = '󰎠 ',
  Variable = '󱄑 ',
}

return {
  my_attach    = my_attach,
  my_exit      = my_exit,
  capabilities = capabilities,
  setup        = setup,
  format       = format,
  symbols       = symbols,
}